ASROCK PRO4 B550 User manual

Version 1.0
Published May 2020
Copyright©2020 ASRock INC. All rights reserved.
Copyright Notice:
No part of this documentation may be reproduced, transcribed, transmitted, or
translated in any language, in any form or by any means, except duplication of
documentation by the purchaser for backup purpose, without written consent of
ASRock Inc.
Products and corporate names appearing in this documentation may or may not
be registered trademarks or copyrights of their respective companies, and are used
only for identication or explanation and to the owners’ benet, without intent to
infringe.
Disclaimer:
Specications and information contained in this documentation are furnished for
informational use only and subject to change without notice, and should not be
constructed as a commitment by ASRock. ASRock assumes no responsibility for
any errors or omissions that may appear in this documentation.
With respect to the contents of this documentation, ASRock does not provide
warranty of any kind, either expressed or implied, including but not limited to
the implied warranties or conditions of merchantability or tness for a particular
purpose.
In no event shall ASRock, its directors, ocers, employees, or agents be liable for
any indirect, special, incidental, or consequential damages (including damages for
loss of prots, loss of business, loss of data, interruption of business and the like),
even if ASRock has been advised of the possibility of such damages arising from any
defect or error in the documentation or product.
is device complies with Part 15 of the FCC Rules. Operation is subject to the following
two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that
may cause undesired operation.
CALIFORNIA, USA ONLY
e Lithium battery adopted on this motherboard contains Perchlorate, a toxic substance
controlled in Perchlorate Best Management Practices (BMP) regulations passed by the
California Legislature. When you discard the Lithium battery in California, USA, please
follow the related regulations in advance.
“Perchlorate Material-special handling may apply, see www.dtsc.ca.gov/hazardouswaste/
perchlorate”
ASRock Website: http://www.asrock.com

AUSTRALIA ONLY
Our goods come with guarantees that cannot be excluded under the Australian
Consumer Law. You are entitled to a replacement or refund for a major failure and
compensation for any other reasonably foreseeable loss or damage caused by our
goods. You are also entitled to have the goods repaired or replaced if the goods fail
to be of acceptable quality and the failure does not amount to a major failure. If
you require assistance please call ASRock Tel : [phone] ext.123 (Standard
International call charges apply)
e terms HDMI® and HDMI High-Denition Multimedia Interface, and the
HDMI logo are trademarks or registered trademarks of HDMI Licensing LLC in the
United States and other countries.

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B550M Pro4
Motherboard Layout
4
3
8
5
9
11
13
14
1
18
19 16
15
22 17
ATXPWR1
Super
I/O
CLRCMOS1
1
PCIE1
HD_AUDIO1
1
CPU_FAN2/WP
SOCKETAM4
F_USB3_1_2
1
CHA_FAN1/WP
1
RoHS
SPK_PLED1
1
DDR4_A1 (64 bit, 288-pin module)
DDR4_A2 (64 bit, 288-pi n module)
DDR4_B1 (64 bit, 288-pi n module)
DDR4_B2 (64 bit, 288-pin module)
PCIE2
PCIE3
HDLED RESET
PLED PWRBTN
PANEL1
M2_2
M2_1
AMD
Promontory
B550
1
USB_3_4
SATA3_4
SATA3_3
SATA3_6
SATA3_5
23
31
CPU_FAN1
CHA_FAN4/WP
1
USB_5_6
29
28
30
ATX12V1
2
ADDR_LED1
1
1
RGB_LED1
7
6
SATA3_1
SATA3_2
10
1
SPI_TPM_J1
1
F_USB3_3_4
24
CHA_FAN2
/WP
25
CHA_FAN3
/WP
RGB_LED2
1
ADDR_LED2
1
CMOS
Battery
LAN
AUDIO
CODEC
12
27 21
CPU
DRAM
VGA
BOOT
20
M2_3
NUT1
1
COM1
26
B550M Pro4
Top:
LIN E IN
Center:
FRONT
Bottom:
MIC IN
RJ-45 LAN
USB 3.2 Gen1
T: USB3
B: USB4
USB 3.2 Gen1
T: USB1
B: USB2
USB 3.2 Gen2
T: USB31_TA_1
B: USB31_TC_1
USB 2.0
T: USB1
B: USB2
PS2
Keyboard/
Mouse
DISPLAY1
HDMI1

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No. Description
1 8 pin 12V Power Connector (ATX12V1)
2 CPU Fan Connector (CPU_FAN1)
3 CPU/Water Pump Fan Connector (CPU_FAN2/WP)
4 2 x 288-pin DDR4 DIMM Slots (DDR4_A1, DDR4_B1)
5 2 x 288-pin DDR4 DIMM Slots (DDR4_A2, DDR4_B2)
6 RGB LED Header (RGB_LED1)
7 Addressable LED Header (ADDR_LED1)
8 ATX Power Connector (ATXPWR1)
9 USB 3.2 Gen1 Header (F_USB3_1_2)
10 SATA3 Connector (SATA3_2)
11 SATA3 Connector (SATA3_1)
12 SATA3 Connector (SATA3_4)
13 SATA3 Connector (SATA3_3)
14 SATA3 Connector (SATA3_5)
15 SATA3 Connector (SATA3_6)
16 System Panel Header (PANEL1)
17 Power LED and Speaker Header (SPK_PLED1)
18 USB 3.2 Gen1 Header (F_USB3_3_4)
19 Chassis/Water Pump Fan Connector (CHA_FAN4/WP)
20 Post Status Checker (PSC)
21 SPI TPM Header (SPI_TPM_J1)
22 USB 2.0 Header (USB_3_4)
23 USB 2.0 Header (USB_5_6)
24 Chassis/Water Pump Fan Connector (CHA_FAN2/WP)
25 Chassis/Water Pump Fan Connector (CHA_FAN3/WP)
26 Clear CMOS Jumper (CLRCMOS1)
27 COM Port Header (COM1)
28 Addressable LED Header (ADDR_LED2)
29 RGB LED Header (RGB_LED2)
30 Front Panel Audio Header (HD_AUDIO1)
31 Chassis/Water Pump Fan Connector (CHA_FAN1/WP)

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B550M Pro4
I/O Panel
No. Description No. Description
1D-Sub Port 9 USB 3.2 Gen2 Type-A Port
2 USB 2.0 Ports (USB_12)* (USB31_TA_1)
3 LAN RJ-45 Port** 10 USB 3.2 Gen2 Type-C Port
4 Line In (Light Blue)*** (USB31_TC_1)
5 Front Speaker (Lime)*** 11 PS/2 Mouse/Keyboard Port
6Microphone (Pink)*** 12 DisplayPort 1.4
7 USB 3.2 Gen1 Ports (USB3_34) 13 HDMI Port
8 USB 3.2 Gen1 Ports (USB3_12) 14 Antenna Bracket
* Please note that the USB_2 consumes auxiliary power (+5VSB) while the other USB ports consume DUAL
Power (+5VDUAL). e USB_2 is optimal for connecting the USB Type speaker and headset.
** ere are two LEDs on each LAN port. Please refer to the table below for the LAN port LED indications.
Activity / Link LED Speed LED
Status Description Status Description
O No Link O 10Mbps connection
Blinking Data Activity Orange 100Mbps connection
On Link Green 1Gbps connection
ACT/LINK LED
SPEED LED
LAN Port
11
10
78913 12
1 2 3 5
14 6
4

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*** Function of the Audio Ports in 7.1-channel Conguration:
Port Function
Light Blue (Rear panel) Rear Speaker Out
Lime (Rear panel) Front Speaker Out
Pink (Rear panel) Central /Subwoofer Speaker Out
Lime (Front panel) Side Speaker Out
Chapter 1 Introduction
ank you for purchasing ASRock B550M Pro4 motherboard, a reliable
motherboard produced under ASRock’s consistently stringent quality control.
It delivers excellent performance with robust design conforming to ASRock’s
commitment to quality and endurance.
1.1 Package Contents
• ASRock B550M Pro4 Motherboard (Micro ATX Form Factor)
• ASRock B550M Pro4 Quick Installation Guide
• ASRock B550M Pro4 Support CD
• 1 x I/O Panel Shield
• 2 x Serial ATA (SATA) Data Cables (Optional)
• 2 x Screws for M.2 Socket (Optional)

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B550M Pro4
Chapter 1 Introduction
ank you for purchasing ASRock B550M Pro4 motherboard, a reliable
motherboard produced under ASRock’s consistently stringent quality control.
It delivers excellent performance with robust design conforming to ASRock’s
commitment to quality and endurance.
1.1 Package Contents
• ASRock B550M Pro4 Motherboard (Micro ATX Form Factor)
• ASRock B550M Pro4 Quick Installation Guide
• ASRock B550M Pro4 Support CD
• 1 x I/O Panel Shield
• 2 x Serial ATA (SATA) Data Cables (Optional)
• 2 x Screws for M.2 Socket (Optional)
Because the motherboard specications and the BIOS soware might be updated, the
content of this documentation will be subject to change without notice. In case any modi-
cations of this documentation occur, the updated version will be available on ASRock’s
website without further notice. If you require technical support related to this mother-
board, please visit our website for specic information about the model you are using. You
may nd the latest VGA cards and CPU support list on ASRock’s website as well. ASRock
website http://www.asrock.com.

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1.2 Specications
Platform • Micro ATX Form Factor
• Solid Capacitor design
• 2oz Copper PCB
CPU • Supports 3rd Gen AMD AM4 Ryzen™ / future AMD Ryzen™
Processors (3000 and 4000 Series Processors)*
* Not compatible with AMD Ryzen™ 5 3400G and Ryzen™ 3
3200G.
• Digi Power design
• 8 Power Phase design
Chipset • AMD B550
Memory • Dual Channel DDR4 Memory Technology
• 4 x DDR4 DIMM Slots
• AMD Ryzen series CPUs (Matisse) support DDR4
4533+(OC)/4466(OC)/4400(OC)/4333(OC)/4266(OC)/
4200(OC)/4133(OC)/4000(OC)/3866(OC)/3800(OC)/3733
(OC)/3600(OC)/3466(OC)/3200/2933/2667/2400/2133 ECC
& non-ECC, un-buered memory*
• AMD Ryzen series APUs (Renoir) support DDR4 4733+
(OC)/4666(OC)/4600(OC)/4533(OC)/4466(OC)/
4400(OC)/4333(OC)/4266(OC)/4200(OC)/4133(OC)/
4000(OC)/3866(OC)/3800(OC)/3733(OC)/3600(OC)/
3466(OC)/3200/2933/2667/2400/2133 ECC & non-ECC, un-
buered memory*
* Please refer to Memory Support List on ASRock’s website for
more information. (http://www.asrock.com/)
* Please refer to page 22 for DDR4 UDIMM maximum
frequency support.
• Max. capacity of system memory: 128GB
• Supports Extreme Memory Prole (XMP) memory modules
• 15μ Gold Contact in DIMM Slots
Expansion
Slot
AMD Ryzen series CPUs (Matisse)
• 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3:
Gen3 x4 mode)*
AMD Ryzen series APUs (Renoir)
• 2 x PCI Express x16 Slots (PCIE1: Gen3x16 mode; PCIE3:
Gen3 x4 mode)*

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B550M Pro4
* Supports NVMe SSD as boot disks
• 1 x PCI Express 3.0 x1 Slot
• Supports AMD Quad CrossFireXTM and CrossFireXTM
• 1 x M.2 Socket (Key E), supports type 2230 WiFi/BT
module
Graphics • Integrated AMD RadeonTM Vega Series Graphics in Ryzen
Series APU*
* Actual support may vary by CPU
• DirectX 12, Pixel Shader 5.0
• Shared memory default 2GB. Max Shared memory supports
up to 16GB.
* e Max shared memory 16GB requires 32GB system
memory installed.
• ree graphics output options: D-Sub, HDMI and
DisplayPort 1.4
• Supports Triple Monitor
• Supports HDMI 2.1 with max. resolution up to 4K x 2K
(4096x2160) @ 60Hz
• Supports DisplayPort 1.4 with max. resolution up to 5K
(5120x2880)@120Hz
• Supports D-Sub with max. resolution up to 1920x1200 @
60Hz
• Supports Auto Lip Sync, Deep Color (12bpc), xvYCC and
HBR (High Bit Rate Audio) with HDMI 2.1 Port (Compliant
HDMI monitor is required)
• Supports HDR (High Dynamic Range) with HDMI 2.1
• Supports HDCP 2.3 with HDMI 2.1 and DisplayPort 1.4
Ports
• Supports 4K Ultra HD (UHD) playback with HDMI 2.1 and
DisplayPort 1.4 Ports
• Supports Microso PlayReady®
Audio • 7.1 CH HD Audio with Content Protection (Realtek
ALC1200 Audio Codec)
• Premium Blu-ray Audio support
• Supports Surge Protection
• PCB Isolate Shielding
• Individual PCB Layers for R/L Audio Channel
• Nahimic Audio

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LAN • PCIE x1 Gigabit LAN 10/100/1000 Mb/s
• Realtek RTL8111H
• Supports Wake-On-LAN
• Supports Lightning/ESD Protection
• Supports Energy Ecient Ethernet 802.3az
• Supports PXE
Rear Panel
I/O
• Antenna Bracket
• 1 x PS/2 Mouse/Keyboard Port
• 1 x D-Sub Port
• 1 x HDMI Port
• 1 x DisplayPort 1.4
• 1 x USB 3.2 Gen2 Type-A Port (10 Gb/s) (Supports ESD
Protection)
• 1 x USB 3.2 Gen2 Type-C Port (10 Gb/s) (Supports ESD
Protection)
• 4 x USB 3.2 Gen1 Ports (ASMedia ASM1074 hub) (Supports
ESD Protection)
• 2 x USB 2.0 Ports (Supports ESD Protection)
• 1 x RJ-45 LAN Port with LED (ACT/LINK LED and SPEED
LED)
• HD Audio Jacks: Line in / Front Speaker / Microphone
Storage • 6 x SATA3 6.0 Gb/s Connectors, support RAID (RAID 0,
RAID 1 and RAID 10), NCQ, AHCI and Hot Plug*
* M2_2 and SATA3_5_6 share lanes. If either one of them is in
use, the other one will be disabled.
• 1 x Hyper M.2 Socket (M2_1), supports M Key type 2280
M.2 PCI Express module up to Gen4x4 (64 Gb/s) (with
Matisse) or Gen3x4 (32 Gb/s) (with Renoir)**
• 1 x M.2 Socket (M2_2), supports M Key type 2280 M.2
SATA3 6.0 Gb/s module and M.2 PCI Express module up to
Gen3 x2 (16 Gb/s)**
** Supports NVMe SSD as boot disks
** Supports ASRock U.2 Kit

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B550M Pro4
Connector • 1 x COM Port Header
• 1 x SPI TPM Header
• 1 x Power LED and Speaker Header
• 2 x RGB LED Headers
* Support in total up to 12V/3A, 36W LED Strip
• 2 x Addressable LED Headers
* Support in total up to 5V/3A, 15W LED Strip
• 1 x CPU Fan Connector (4-pin)
* e CPU Fan Connector supports the CPU fan of maximum
1A (12W) fan power.
• 1 x CPU/Water Pump Fan Connector (4-pin) (Smart Fan
Speed Control)
• 4 x Chassis/Water Pump Fan Connectors (4-pin) (Smart
Fan Speed Control)
* e Chassis/Water Pump Fan supports the water cooler fan
of maximum 2A (24W) fan power.
* CPU_FAN2/WP, CHA_FAN1/WP, CHA_FAN2/WP, CHA_
FAN3/WP and CHA_FAN4/WP can auto detect if 3-pin or
4-pin fan is in use.
• 1 x 24 pin ATX Power Connector
• 1 x 8 pin 12V Power Connector
• 1 x Front Panel Audio Connector
• 2 x USB 2.0 Headers (Support 4 USB 2.0 ports) (Supports
ESD Protection)
• 2 x USB 3.2 Gen1 Headers (Support 4 USB 3.2 Gen1 ports)
(Supports ESD Protection)
BIOS
Feature
• AMI UEFI Legal BIOS with GUI support
• Supports “Plug and Play”
• ACPI 5.1 compliance wake up events
• Supports jumperfree
• SMBIOS 2.3 support
• CPU, CPU VDDCR_SOC, DRAM, VPPM, 1.05V_PROM_
S5, 2.5V_PROM, +1.8VSB, VDDP Voltage Multi-adjustment

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Hardware
Monitor
• Temperature Sensing: CPU, CPU/Water Pump, Chassis/
Water Pump Fans
• Fan Tachometer: CPU, CPU/Water Pump, Chassis/Water
Pump Fans
• Quiet Fan (Auto adjust chassis fan speed by CPU tempera-
ture): CPU, CPU/Water Pump, Chassis/Water Pump Fans
• Fan Multi-Speed Control: CPU, CPU/Water Pump,
Chassis/Water Pump Fans
• Voltage monitoring: +12V, +5V, +3.3V, CPU Vcore, CPU
VDDCR_SOC, DRAM, VPPM, 1.05V_PROM_S5, +1.8V,
VDDP
OS • Microso® Windows® 10 64-bit
Certica-
tions
• FCC, CE
• ErP/EuP ready (ErP/EuP ready power supply is required)
Please realize that there is a certain risk involved with overclocking, including adjusting
the setting in the BIOS, applying Untied Overclocking Technology, or using third-party
overclocking tools. Overclocking may aect your system’s stability, or even cause damage to
the components and devices of your system. It should be done at your own risk and expense.
We are not responsible for possible damage caused by overclocking.
* For detailed product information, please visit our website: http://www.asrock.com

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B550M Pro4
is is a Micro ATX form factor motherboard. Before you install the motherboard,
study the conguration of your chassis to ensure that the motherboard ts into it.
Pre-installation Precautions
Take note of the following precautions before you install motherboard components
or change any motherboard settings.
• Make sure to unplug the power cord before installing or removing the motherboard.
Failure to do so may cause physical injuries to you and damages to motherboard
components.
• In order to avoid damage from static electricity to the motherboard’s components,
NEVER place your motherboard directly on a carpet. Also remember to use a grounded
wrist strap or touch a safety grounded object before you handle the components.
• Hold components by the edges and do not touch the ICs.
• Whenever you uninstall any components, place them on a grounded anti-static pad or
in the bag that comes with the components.
• When placing screws to secure the motherboard to the chassis, please do not over-
tighten the screws! Doing so may damage the motherboard.
Chapter 2 Installation

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2.1 Installing the CPU
Unplug all power cables before installing the CPU.
2
1

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B550M Pro4
3

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14
2.2 Installing the CPU Fan and Heatsink
Aer you install the CPU into this motherboard, it is necessary to install a larger
heatsink and cooling fan to dissipate heat. You also need to spray thermal grease
between the CPU and the heatsink to improve heat dissipation. Make sure that the
CPU and the heatsink are securely fastened and in good contact with each other.
Installing the CPU Box Cooler SR1
Please turn o the power or remove the power cord before changing a CPU or heatsink.
1
2

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B550M Pro4
3
4
CPU_FAN1

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Installing the AM4 Box Cooler SR2
1
2

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B550M Pro4
3

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*e diagrams shown here are for reference only. e headers might be in a dierent position on
your motherboard.
4
CPU_FAN1